1. Field of the Invention
This invention relates to a process for producing an acrylate or methacrylate of the formula: ##STR4## wherein R.sub.1 is hydrogen or a methyl group and A and B are each independently unbranched or branched alkylene groups with 2 to 5 carbon atoms.
2. Description of the Prior Art
Compounds of the Formula (I) may be obtained by the process of U.S. Pat. No. 2,871,223 by converting acrylic or methacrylic chloride with hydroxyalkyl-imidazolidin-2-ones in the presence of a tertiary nitrogen base, whereby a stoichiometric amount of the hydrochloride of the tertiary nitrogen base is also generated.
EP 0 236 994 A1 describes a process for producing an acrylate and methacrylate of the formula (I), by converting the acrylate or methacrylate with 1-(hydroxyalkyl)-imidazolidin-2-ones in the presence of either a titanium alcoholate or a titanium, zirconium, iron, or zinc chelating agent using 1,3-dicarbonyl compounds as a transesterification catalyst.
EP-A 0 433 135 and EP-A 0 453 638 describe the use of a diorganotinoxy compound as a transesterification catalyst for the conversion of an acrylate and methacrylate with a hydroxyalkyl imidazolidin-2-one into a compound of the formula
In all these processes, the metal catalyst must be separated from the reaction mixture after conclusion of the conversion. When a tetraalkyl titanate or dialkyl tin oxide is used, the separation may be achieved by addition of water. Metal (hydro)oxides, such as TiO.sub.2, may be produced from the corresponding titanate which can then be separated by filtering or centrifuging. Unfortunately, these hydrolyzed transesterification catalysts cannot be reused after separation. While dialkyl tin oxides can be separated and reused as transesterification catalysts; the separation step necessitates that a relatively large amount of water first be added and then removed from the reaction product.
DE-OS 34 23 441 and DE-OS 34 23 443 describe processes for producing esters using catalyst systems KS that are made up of lithium/calcium compounds.